Meta Tag Manager
Installation and Configuration
I don't believe the Meta Tag Manager will do separate descriptions and keywords for separate "front-end" pages, a work around would be to modify the "articles" and/or "lessons" templates and add your own.
You can use an assign function above the header include function to do this, something like:
Keywords:
{assign var="page_keywords" value="your,keywords,here"}
Description:
{assign var="page_description" value="your description here"}
Then in your skins/YOURSKIN/meta.tpl file, find this:
{if isset($meta)}
{foreach from=$meta key="mname" item="mvalue"}
<meta name="{$mname}" content="{$mvalue}" />
{/foreach}
{/if}
and change it to this:
{if (isset($page_keywords) && strlen($page_keywords) > 0) && (isset($page_description) && strlen($page_description) > 0)}
<meta name="keywords" content="{$page_keywords}">
<meta name="description" content="{$page_description}">
{elseif isset($meta)}
{foreach from=$meta key="mname" item="mvalue"}
<meta name="{$mname}" content="{$mvalue}" />
{/foreach}
{/if}
Hope this helps,
Douglas